This paper extends the classical model of sales (Varian, 1980; Rosenthal, 1980) by adding product differentiation. Instead of uninformed (i.e. loyal) customers, our setting features “variety ...seekers”. These consumers regard the products as imperfect substitutes. As in the original model, the firms also serve “bargain seekers” who buy the cheapest product. The discontinuous demand structure precludes any pure-strategy equilibria. We characterize the symmetric mixed-strategy equilibrium of the modified game. In contrast to the original model, the upper bound on prices and the equilibrium expected profits are decreasing in the mass of bargain seekers.
•Product differentiation has substantive consequences for price dispersion.•The bounds on prices depend on the equilibrium expected price.•Expected profits and the bounds on prices decrease with the mass of bargain seekers.•The setting nests the classical model of sales as a special case.
Infectious complications of the diabetic foot may be influenced by impaired renal function and by immunosuppression therapy.
Aims: To assess differences in microbial findings and resistance to ...antibiotics between transplant recipients, hemodialysis patients, and other patients with the diabetic foot.
Methods: 207 patients treated in the foot clinic for diabetic ulcers from 12/1998 to 12/1999 were included into this retrospective study. Patients were divided into three groups (transplant, dialysis, and other patients). Occurrence of individual bacterial species and resistance to antibiotics was compared between study groups.
Results: Study groups did not differ significantly in ulcer grades defined by the Wagner classification or in the mean number of pathogens per patient. The prevalence of individual microorganisms did not differ between the study groups. However, the study groups differed significantly in the occurrence of microbial resistance to antibiotics. Transplant patients had more frequently
Staphylococcus aureus resistant to oxacillin (
P<.01), imipenem (
P<.01), co-trimoxazole (
P<.01),
Enterococcus species resistant to ampicillin (
P<.01), piperacillin (
P<.01), and dialysis patients had more frequently
Pseudomonas species resistant to piperacillin (
P<.05) and cefpirom (
P<.05) in comparison with the other two groups.
Conclusions: Transplant patients had significantly more resistant microorganisms in comparison with dialysis and other patients with the diabetic foot. Empiric antibiotic selection based on general population data should be modified in transplant patients with diabetic foot according to actual susceptibility to antibacterial drugs.
This paper studies the behavior of a consumer whose time preferences exhibit globally decreasing impatience. We ask how well this behavior could be approximated with quasi-hyperbolic discounting. We ...find that a quasi-hyperbolic approximation can reproduce the consumer’s equilibrium strategies and their local comparative statics. However, such an approximation would provide biased assessments of measures to mitigate excessive consumption. We identify a range of biases relating to investment in illiquid assets, and to corrective taxes on sin goods. The quantitative implications of these biases are evaluated in numerical examples. For plausible parameter values, the quasi-hyperbolic approximation significantly overstates the effectiveness and the welfare consequences of the responses to excessive consumption.
Artificial insemination (AI) as a part of assisted reproductive technologies represents the oldest and most widespread method used to accelerate genetic progress in all domestic animals. After its ...first implementation in ovine reproduction and almost 80 years afterward, AI is continuously used for improving the genetic merit, utilizing either fresh or short-time chilled semen. Nevertheless, regardless of the semen used for insemination, the conception rate (CR) is still lower in comparison to natural service. At least two factors are commonly thought to limit the success of the AI and reduce the CR: (1) failure of placing the semen directly into the uterus due to the specific anatomic structure of the ewe’s cervix; (2) lower viability of ram spermatozoa during cryopreservation (<30% progressively motile spermatozoa after thawing). This review elaborates on recent studies that aimed to achieve acceptable CR through the implementation of cervical or intrauterine insemination: deep intracervical, intrauterine trans-cervical, and intracornual. Several hormonal treatments (oxytocin, estrogen, or prostaglandin) were evaluated on inducing cervical dilation that facilitates insemination. A comprehensive analysis was given to the effects of several antioxidants (GSSG, GSH, and cysteine) supplemented in ram semen-freezing media. Sex-sorted ram semen fertility rate results were presented from our studies.
Inadequate saving for retirement and excessive consumption of sin goods have both been attributed to present bias. However, demonstrations that present bias does produce these effects have typically ...been confined to special cases. Previous research has focused on specific forms of discounting (such as quasi-hyperbolic) and on infinite planning horizons. Our paper investigates the implications of general present bias for consumption rules in a setting with an arbitrary number of periods. We show that equilibrium rules need not always prescribe higher consumption than precommitment decision rules do for the same stock. However, there are still social gains to discouraging consumption, and so rationales for commitment devices and paternalist interventions do generalize.
The health condition of the mammary gland is highly crucial for obtaining good quality colostrum. The lactoferrin (LF), as an iron-binding protein, plays a key role in the defense mechanisms of the ...mammary gland due to its’ bacteriostatic properties. The study aimed to investigate the factors affecting the LF concentration in the bovine colostrum milk during the postpartum period, and the effect of somatic cell count (SCC) on the LF concentration and milk composition. The cows were randomly selected at a dairy farm in Pelagonia region. Colostrum samples from 12 cows were collected. Samples were taken at different time intervals after parturition, 1, 6, 12, 24, 48, 72, 96, and 120 h after parturition. Cows in their second parity were found to have higher levels of LF compared to cows in the third and higher parity (p>0.05). Time had a significant effect on the LF concentration (p<0.01), with the highest value recorded 1 h after parturition remaining stable for one hour. LF concentration and SCC in the colostrum showed a weak positive correlation (r=0.40; p<0.01). The highest LF concentration was noticed when SCC was above 800,000 cells/mL. In conclusion, the colostrum LF concentration was significantly affected by the interactions of the two factors, i.e., time after parturition and SCC (p<0.05). Milk composition was affected by elevated SCC. Parity showed no association with LF. The SCC can be used as a reliable means of assessing colostrum quality.
Choices are sometimes distorted by internalities or externalities. This paper considers a setting in which the distortion cannot be taxed directly, and asks how a policymaker should choose a proxy ...variable to tax instead. We derive a criterion for when one proxy should be preferred to another, and consider a range of factors with implications for this criterion. These factors are (i) sensitivity to the tax rate, (ii) how accurately the taxed variable approximates the distorted variable, (iii) susceptibility to offsetting behavior, and (iv) consumer heterogeneity. Our analysis is illustrated with a comparison between ad valorem and volumetric taxes on sugar‐sweetened beverages.
The bovine kappa-casein (κ-CN) is a phospho-protein with 169 amino acids encoded by the
gene. The two most common gene variants in the HF breed are
and
while
has been found with lower frequency. The ...aim of this study was to optimize a laboratory method for genotyping of these three alleles as well as to determine their genotype and allele frequencies in the HF cattle population in the Republic of North Macedonia. Genomic DNA was extracted from full blood from 250 cows. The target DNA sequence was amplified with newly designed pair of primers and the products were subjected to enzymatic restriction with
III and
III endonucleases. Genotype determination was achieved in all animals. The primers successfully amplified a fragment of 458 bp and the digestion of this fragment with both endonucleases enabled differentiation of five different genotypes with the following observed frequencies: AA (0.39), AB (0.29), BB (0.16), AE (0.10), and BE (0.06). The estimated allele frequencies were:
(0.584),
(0.336) and
(0.08). The observed genotype frequencies differed significantly (P<0.01) from those that would be expected under HW equilibrium, while the fixation index (
=0.17) indicated moderate heterozygosity deficiency. Nevertheless, the
allele was present with relatively high frequency which should be used to positively select for its carriers, since increasing its frequency could help to improve the rheological properties of the milk intended for cheese production.
Aluminum offers engineers weight saving advantages in their product design. However, aluminum has poor wear and friction properties. In addition, the surface oxide layer of this chemically active ...metal, which gives it the corrosion resistance, makes it a very difficult metal to plate 1. Specific pre-treatment must be applied to remove the oxide layer from the aluminum surface. The nanodiamond particles additionally facilitates the process of chromium deposition. The object of this study is to evaluate the impact of nanodiamonds on the mechanical properties of the chromium coating plated on
We examine how a tax on cigarettes would be affected by endogeneity of their addictiveness. In our model, the rationale for government intervention is based on internalities and externalities. While ...a corrective tax could be imposed to address these two distortions, it may result in excessive nicotine consumption per cigarette. This suggests that tax rates should be moderated. We consider two types of behavior that affect the addictiveness of cigarettes. First, producers can manipulate the nicotine content of tobacco products. Second, consumers are able to adjust the intensity of their smoking. We show that there may still be a case for a corrective tax. However, tax policies and attainable welfare depend on whether the nicotine dose from each cigarette is influenced by producers or consumers.
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